A Pulsar calculator watch (photo: The Smithsonian) There were a few problems. First, the watch was thick. Despite its size, it had tiny keys, so you had to use a little stylus to push the keys ...

By then a number of other handheld calculators were also hitting the market. In November 1970, the first calculator-on-a-chip, the Mostek MK6010, was announced, followed in February 1971 by the ...